Physical property database retrieval system

ABSTRACT

A system to retrieve fluid property data consisting of a single common fluid property database interface and unique files to allow for efficient retrieval of fluid property data from the AIChE DIPPR database or any other fluid properties database from the hard disk storage area of a general data processor. A text file (1) of fluid descriptions for each fluid category is used to define the selections in the fluid description list box (4). A text file (2) of fluid properties for each fluid property category is used to define the selections in the fluid property list box (5). The selections in each list box change according to the category of fluid description and fluid property that is selected. A Get DIPPR Data command (6) then retrieves all fluid property data for the selected fluid description and fluid property in one reading of the AIChE DIPPR database or any other fluid properties database of similar format by utilizing a unique record number reference file (3) so that only the selected fluid&#39;s data is read from the database. This provides for quick and easy access to DIPPR fluid property database information that is vital for optimal system design and system operation in the process industries.

BACKGROUND--FIELD OF THE INVENTION

The present invention relates to database retrieval applications andmore specifically to engineering fluid property database retrieval froma developed fluid property database.

BACKGROUND OF THE INVENTION--PRIOR ART

The AIChE DIPPR database contains 39 constant and temperature dependentproperties for 1284 fluids with thermodynamic, physical, and transportproperty data given for pure chemicals of high industrial priority. Thedatabase was prepared by the Pennsylvania State University for theDesign Institute for Physical Property Data (DIPPR) which is acooperative project sponsored by 25 major chemical manufacturers andrelated companies under the auspices of the American Institute ofChemical Engineers (AIChE) and copyrighted by the AIChE for distributionthrough authorized distributors. The Fortran data retrieval system forthe DIPPR database supplied by DIPPR was originally developed for usewith punch cards on a mainframe computer of the early 1980's.Distributors of the DIPPR database have traditionally relied heavily onthis outdated interface for retrieval of the DIPPR data. RetrievingDIPPR fluid properties data through this computer access programrequires keyboard input of the desired selection from a list of choicesat least seven different times to retrieve just a single data value. Toretrieve the molecular weight of a fluid from DIPPR using the Fortransupplied retrieval system, the output file name is specified, the optionmode to select the fluid is selected, the type of fluid description nameis entered, the fluid name is entered, the mode is switched to quitfluid description entry, the mode is switched to retrieve fluidproperties, the fluid property type needs to be entered, and then thedata result is displayed. For temperature dependent fluid property data,additional steps are also involved. If the fluid type is changed, theprocess has to be repeated from the beginning. Even if the same fluid isbeing used, several steps must be repeated to retrieve another datavalue, and the database needs to be read for each new data valuerequested. These types of interfaces for the DIPPR database haveprevented the widespread use of this widely renowned fluid propertydatabase due to the relative difficultly associated with retrieving anyfluid property data using outdated interface designs. The lack of anefficient data retrieval system to retrieve the fluid property data hasalso required more of the general data processor being used for dataretrieval than is necessary, as well.

SUMMARY OF THE INVENTION--OBJECTS AND ADVANTAGES

The Invention consists of a single common fluid property databaseinterface along with unique reference files to allow for the retrievalof all data for a particular fluid property category with only onereading of the DIPPR database or any other fluid property database ofsimilar format residing on the hard disk storage area of a generic dataprocessor. The general data processor is a personal computer systemdesigned to operate under the MSDOS®, Windows®, or Macintosh® operatingsystems and would consist of a display monitor, keyboard, mouse pointingdevice, printer, and central processing unit with random access memory,floppy disk drive, and hard disk drive. The single common fluid propertydatabase interface consists of a list box for selecting the fluiddescription and a list box for selecting the fluid property. Theselections in each list box change according to the category that isselected for each list through option buttons or menus. Once the desiredfluid description and fluid property have been selected, a singlecommand will retrieve the fluid property data in one reading of thefluid property database using a unique record number reference file andthe results displayed on the single common fluid property databaseinterface for each fluid property as it is selected from the list boxwithout again reading the fluid property database until either the fluiddescription or fluid property category is changed. The example givenearlier to retrieve the molecular weight of a fluid would only requirethree selections using this fluid property database retrieval systemutilizing the default settings versus seven steps for the DIPPR suppliedFortran retrieval system. The use of a modern computer interface designincluding list boxes, option buttons, pull-down menus, and commandbuttons in the single common fluid property database retrieval interfaceallows the user to become quickly efficient in using this system sincethese designs are found in many other commercial software packages thatare commonly used on current graphical-based operating systems such asMicrosoft Windows®. These interface designs have proven to provideincreased use and proficiency over single step keyboard entry systems asis used in MSDOS® and the DIPPR supplied Fortran retrieval system.Additionally, the use of a record number reference file to require onlyone reading of the fluid property database for a particular fluiddescription and fluid property category reduces the requirements of thegeneral data processor to efficiently retrieve fluid property data fromthe DIPPR fluid property database.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the invention become apparent upon reading thefollowing detailed description and upon referral to the drawings ofwhich:

FIG. 1 describes the method to create a text file for each category offluid descriptions to provide the selections available in the fluiddescription list box.

FIG. 2 describes the method to create a text file for each category offluid properties to provide the selections available in the fluidproperty list box.

FIG. 3 describes the method to create a record number reference filethat is used to open the fluid property database at the point where theselected fluid's property data begins.

FIG. 4 is a block diagram describing the method of retrieving all fluidproperty data for a particular fluid and fluid property category in onereading of the database using the files created in FIG. 1-3.

FIG. 5 is a diagram which describes the single common fluid propertydatabase interface to retrieve and display fluid properties.

REFERENCE NUMERALS IN DRAWINGS

1. Fluid Description List Files

2. Fluid Property List Files

3. Record Number Reference File

4. Fluid Description List Box

5. Fluid Property List Box

6. Get DIPPR Data Command Button

While the invention is susceptible to various modifications andalternative forms, a specific embodiment of the invention is describedin detail below. This description is not intended to limit the inventionto the particular form disclosed, but the invention is to cover allmodifications and alternatives falling within the scope of the inventionas defined by the claims below. Such modifications could include the useof menus to select the description and property categories instead ofoption buttons, the use of keyboard commands instead of selecting acommand button to search the fluid property database, etc.

DESCRIPTION OF PREFERRED EMBODIMENT

Three custom files are required for the use of the process describedbelow. To assign names to the fluid description list box 4, the creationof a text file 1 for each category of fluid descriptions that areavailable in DIPPR or any other fluid property database being used isrequired as shown in FIG. 1. These files 1 are created using a temporaryutility program which searches the DIPPR SOURCE.DAT file or main fluidproperty database file for a particular fluid description category andthen writes all occurrences for each format TYPE$ to a text file 1 foreach category with one line in the text file 1 representing each fluiddescription in string format. Next, the creation of a text file 2 foreach category of fluid properties available in the fluid propertiesdatabase is required to assign names to the fluid properties list box 5as detailed in FIG. 2. This is manually keyed for each fluid propertycategory type to provide one line in the text file 2 for each fluidproperty that is available in string format. When a fluid description orfluid property category item is selected by either option buttons ormenu choices, the appropriate text file corresponding to the selectedcategory is read from the hard disk storage area of the general purposedata processor and these string values are assigned as the newselections in the appropriate list box as shown in FIG. 4 steps A & C.

To limit the reading of the DIPPR database or any other fluid propertydatabase to only the selected fluid's data, the creation of a recordnumber reference file 3 which lists each fluid DIPPR reference ordatabase reference number next to the first record number where thatfluid's property data appears in the database is required as shown inFIG. 3. This is done using a temporary utility program which is designedto read the entire DIPPR SOURCE.DAT file or main fluid property databasefile and to write the first occurrence of each DIPPR database referencenumber or other fluid property database reference number and its currentrecord number to the RECNUM.DAT text file 3. Since the DIPPR database isformatted so that all data for a particular fluid are grouped together,the utility program skips each data line following the first occurrenceof the DIPPR reference number until another DIPPR reference number isencountered. The assignment of LASTNUM=DIPPRNUM in FIG. 3 allows for thecapture of the reference number of the last record in the database sothat it can be compared to the newly assigned DIPPRNUM in the nextrecord number of RN=RN+1. If these values are not equal, then a newreference number has been found which marks the beginning of anotherfluid's properties and this reference number and its record number iswritten to the RECNUM.DAT file 3. This process is repeated until theentire database has been scanned and the record number reference file 3is completed. For fluid property databases which do not group eachfluid's properties all together, the database records would need to bereorganized accordingly before creation of the record number referencefile 3 as detailed above.

The process of retrieving fluid property data can now begin as isdetailed in FIG. 4. When the fluid description category is changed, thecurrent selections in the fluid description list box 4 "FluidList" areremoved and the Description.Dat file 1 which corresponds to the selectedcategory that was created earlier in FIG. 1 is opened and its stringvalues assigned as the new selections available in the fluid descriptionlist box 4 "FluidList". Then when the "FluidList" fluid description listbox 4 is clicked on or selected the subroutine FluidList₋₋ Click isinvoked which assigns the selected item in the list "FluidList.Text" tothe string variable FLUIDNAME in the random access memory of the generaldata processor as detailed in FIG. 4 steps A and B.

When the fluid property category is changed, the current selections inthe fluid property list box 5 "PropList" are removed and theProperty.Dat file 2 which corresponds to the selected category which wascreated earlier in FIG. 2 is opened and its string values assigned asthe new selections available in the fluid property list box 5"PropList". Then when the "PropList" fluid property list box 5 isclicked on or selected the subroutine PropList₋₋ Click is invoked whichassigns the selected item in the list "PropList.Text" to the stringvariable PROPNAME in the random access memory of the general dataprocessor as detailed in FIG. 4 steps C and D.

When selections have been made in the fluid description list box 4 andthe fluid property list box 5, the Get DIPPR Data command 6 orequivalent command can then be selected as detailed in FIG. 4 step E.The GetlndexNum subroutine is invoked first which opens the DIPPRINDEX.DAT file on the hard disk storage area of the general dataprocessor as a random file of length=132 and then scans this file untilthe area assigned for fluid descriptions (location 11 thru 51) matchesthe FLUIDNAME string variable assigned by the fluid description list box4 in the FluidList₋₋ Click subroutine. When a match is found, the DIPPRreference number is retrieved (location 1 thru 4) and assigned to thevariable DATANUM. Then the GetRecordNum subroutine is invoked whichopens the RECNUM.DAT record number reference file 3 created in FIG. 3.This file is scanned until the RECNUM record number in the RECNUM.DATfile matches the DATANUM which corresponds to the fluid descriptionselected in the fluid description list box 4. When a match is found, therecord number RN next to the RECNUM reference number can then be used toopen the SOURCE.DAT file or main fluid property database file at theprecise record number where the selected fluid's property data begins.

Then, the GetPropTypen subroutine is invoked which opens the SOURCE.DATor main fluid property database file at the record number RN assigned bythe GetRecordNum subroutine. All the data for the selected fluidproperty category is then retrieved according to the format of thedatabase being used. Parameters are used when applicable and theretrieved values of the fluid property data are stored as variables inthe random access memory of the general data processor. The database isread as long as the CURRENTNUM representing the current databasereference number equals the DATANUM representing the reference number ofthe fluid selected in the fluid description list box 4. When CURRENTNUMdoes not equal the DATANUM, then all data on the selected fluid has beenexhausted and the database is closed. The fluid properties are thendisplayed on a single common fluid property database interface shown inFIG. 5 from the random access memory of the general data processor as afluid property is selected from the fluid property list box 5 withoutagain reading the fluid properties database unless the fluid descriptionor fluid property category is changed. This method provides directaccess of all fluid property data while requiring the minimum amount oftime required by the general data processor to read the DIPPR SOURCE.DATfile.

The steps in the single common fluid property database interface toretrieve fluid property data from the hard disk storage area of ageneral data processor shown in FIG. 5 relate to the steps shown in FIG.4. First the fluid description category is selected and the fluiddescription selected from the fluid description list box 4 whichcorresponds to steps A and B in FIGS. 4 and 5. Then the Fluid categoryis selected and the fluid property selected from the fluid property listbox 5 which corresponds to steps C and D in FIGS. 4 and 5. When the GetDIPPR Data command 6 is selected, step E in FIG. 4 and FIG. 5 is invokedto retrieve the fluid property data and display the results on thesingle common fluid property database interface. Then any fluid propertyin the current fluid property list can be immediately displayed from therandom access memory of the general data processor by selecting an itemfrom the fluid property list box 5.

In summary, this process of retrieving fluid property data in onereading of the database with the single common fluid property databaseinterface utilizing a unique record number reference file 3 providesquicker and easier access to the fluid property data in the DIPPRdatabase whose data is vital in the design and optimization of processsystems in the process industries. This process could also be useful forother types of databases which can be formatted to the format used bythe DIPPR database.

What is claimed is:
 1. A process of data retrieval of physicalproperties of an element from an existing physical property databaseresiding on a hard disk storage area of a general data processor withrandom access memory to enable said general data processor to retrieveall said physical properties of a physical property description categoryin one reading of said existing physical property database and todisplay said physical properties using a single common physical propertydatabase interface displayed on a display monitor of said general dataprocessor without making any format structure modifications to saidexisting physical property database, said process comprising the stepsof:a. creating and storing in said hard disk storage area an elementdescription list file for each element description category available insaid existing physical property database; b. displaying on said displaymonitor the description of each said element of a selected said elementdescription list file in an element description list box within saidsingle common physical property database interface; c. selecting anelement from said element description list box displayed on said displaymonitor wherein element descriptions listed in said element descriptionlist box change when a said element description category is changed; d.creating and storing in said hard disk storage area a physical propertylist file for each said physical property description category availablein said existing physical property database; e. displaying on saiddisplay monitor the description of each said physical property of aselected said physical property list file in a physical property listbox within said single common physical property database interface; f.selecting said physical properties of said selected element from saidphysical property list box displayed on said display monitor whereinsaid physical property list box changes when said physical propertydescription category is changed; g. generating and storing on said harddisk storage area a unique record number reference file for saidexisting physical property database; h. identifying a record number tobegin searching for said physical properties within said existingphysical property database residing on said hard disk storage area ofsaid general data processor for said selected element utilizing saidunique record number reference file; i. retrieving all of said physicalproperties in said existing physical property database for said selectedelement with a single read of said existing physical property data baseand storing said physical properties in said random access memory usinga single command on said single common physical database interface; andj. displaying on said display monitor said stored physical properties assaid physical properties are selected within said physical property listbox without again having to read said existing physical propertydatabase.